Dehumidifier Calculation in Excel

This excel sheet calculates the dehumidifier capacity for reducing the humidity in a warehouse, cold room, warehouse, industries etc.

How to calculate the capacity of dehumidifier?

In layman’s language, dehumidification process is the removal of water from the surrounding air. Bringing down the humidity levels means reducing the moisture content in the air.

So the capacity of a dehumidifier is defined as its capacity to remove the water content. eg. a dehumidifier with a capacity of 24 litres per day means it can remove 24 litres of water in a day. So effectively, moisture content totalling 24 litres can be removed in a day by this particular dehumidifier.

Steps for calculating dehumidification capacity and selecting the right dehumidifier

For any applications covering residential, commercial or industrial, you can calculate the dehumidification capacity and select a suitable dehumidifier as per the following steps:

Please note that the capacity of a dehumidifier varies as per the temperature. Hence never select a dehumidifier based on its maximum specified capacity. Please look for the performance chart of the dehumidifier. This will indicate a performance graph at different temperatures. You may select the right capacity at your room temperature.

Details required to calculate de-humidification capacity

In order to calculate the required capacity of a dehumidifier, you need to collect the following details:

The size of the room in cubic meters.

Present temperature of the area, preferably the maximum recorded temperature reading.

Present or maximum humidity levels without a dehumidifier in %RH (You can use a data logger or hygro meter to find out the same. Data logger will record the data over a time. Hygrometer will not record the data, but only will display on the screen.)

Required humidity level to which you want to reduce the humidity levels in %RH.

Method for calculating de-humidification capacity

All the normal humidity measuring instruments will indicate the humidity levels in %RH. This has to be converted to absolute humidity which means the amount of moisture per cubic meter. Absolute humidity will be automatically calculated in the excel sheet for Sl. no. 3 & 4 defined above.

The difference between the absolute humidity of 3&4 above gives the moisture content to be removed from 1 cubic meter.

Multiply this result by the volume of the room which will provide the total volume of the water to be removed from the room to bring the humidity down to the desired levels.

How to calculate the capacity of dehumidifier in Excel?

The above entire calculation is formulated in this free excel sheet. You need to enter only the input values as above and the results are automatically generated.

This is equal to 0.455 kilograms per hour or 0.455 litres per hour. Calculating values per day, this amounts to 10.92 kg per day or 10.92 litres per day.

Hence you can select a dehumidifier with a capacity of 10.92 litres per day to meet your requirement. Among our various models, you can select the nearest model TTK 40E which has a capacity of 12 litres per day at 30°C.

How to calculate which dehumidifier to use?

Also, you can use our online calculator for dehumidifier capacity calculation. Upon calculating the required capacity you can use the selection chart on the same page to select a suitable model. For bigger rooms, it is better to select multiple smaller models instead of one big model. This is to improve the air circulation. eg. If you provide one big dehumidifier of 300 liters per day, in one location of a warehouse it will not provide enough air circulation around the warehouse. It will be better to provide 4 dehumidifiers each of 75 liters per day.

How to calculate the dehumidifier capacity in pint/day?

The above excel sheet is providing the results in litres per day. If you want to convert the capacity into pints per day, please use proper conversion. For conversion into US pints, you may use the multiplication factor of 2.11337642 to derive pint per day from litre per day.

Please fill up the form to instantly receive the calculation sheet. If you do not receive download link, please send us email at contact.en@vackerglobal.com.

24 comments on “Dehumidifier Calculation in Excel”

I am looking for dehumidification equipment for accommodation on an offshore installation. The equipment should be capable of handling the humidity over 3 floors, individual rooms and corridors along with control rooms etc, do you have a technical person i could speak to?

300 to 400 liter per day will be very huge for a room. IF you are planning a duct system for the whole house, probably you will require this much capacity. Did you calculate using our calculator? What was result you obtained?

Can you please help me with this calculation.I need to have my relative humidity at 50% . So I have to remove cca. 6g/kg water from the air (T=15°C relative humidity is 90%)
The size of the room is 150m3, so in the room is 180kg of air(in tables). This means that I need to remove 1080g of water from the air( 180kg * 6g/kg= 1080g).
This means that in a room of 150m3 to reduce the humidity from 90 to 50% takes only 1080g of water?
With your calculator the result would be 0.7694 kg/h or 18.4656 kg in a day?
Can you help me with this problem? Thank you

I’m trying to dehumidify a unconditioned warehouse for mechanical equipment and motors. Area 7500sqft by 20’h. Warehouse is located 10 miles from coast. (Gulf of Mexico) Would like to keep the room at roughly 70% RH. Room has ventilation fans at the roof line.